Cadillac Owners Forum banner

1 - 6 of 6 Posts

·
Registered
1994 STS
Joined
·
18 Posts
Discussion Starter #1
So I have the same " service ride control " message as everybody else and it sits low in the back. I would like to keep the original air ride system and was wondering if the problem is most likely just in the back shocks ? Or would I have to change the compressor and other parts of the air ride system as we'll? Am I better off just getting an aftermarket conversion kit ? Any feedback on brands ? Any help appreciated thanks. Also is there a diagram for the air ride system ?
 

·
Registered
2001 Seville STS, 1990 Seville (RIP), 1972 Sedan Deville
Joined
·
26,323 Posts
An issue specifically with the leveling system (it's not air ride) won't trigger a code or message. For that, you'll have to pull your codes.

Do you hear your ELC pump running, trying to level the rear?
 

·
Administrator
2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
Joined
·
69,906 Posts
It's not "air ride" in the suspension controls sense. The struts and shocks are normal (but active) hydraulic units with car weight carried by coil springs. The "air" is used in the rear shock bladders only to control height changes due to extra weight in the trunk or rear seat.
 

·
Master of the Dark Art of Diagnostics
2003 DHS - two-2002 DHS, 2003 SLS, 1995 Sedan DeVille, 1989 Coupe DeVille
Joined
·
19,867 Posts
So I have the same " service ride control " message as everybody else and it sits low in the back. I would like to keep the original air ride system and was wondering if the problem is most likely just in the back shocks ? Or would I have to change the compressor and other parts of the air ride system as we'll? Am I better off just getting an aftermarket conversion kit ? Any feedback on brands ? Any help appreciated thanks. Also is there a diagram for the air ride system ?
==========================
I have the same " service ride control " message as everybody else
and it sits low in the back

you have two completely unrelated problems -
let's deal with them one at a time -

your car came with electronic - or ACTIVE struts and shocks -
I doubt you'll find ANY OEM replacements anymore -

the ACTIVE struts/shocks constantly changed
how firm or soft the units rode - as you drive -

NOT to be confused with the rear ELC -
Electronic Level Control shocks -

typically - the electronics part of the struts/shocks fail -
and that is what causes the SERVICE SUSPENSION message -

-------------------

there are two methods of fooling the suspension system -
into believing the electronics part of the struts and shocks are OK -
depending on the system your car has -

I'm not sure which your specific car has -

the older system - Speed Sensing Suspension -
you install a relay in the trunk - takes 15 minutes to do -

the newer F45 - CVRSS -
uses one small resistor for each strut and shock -

these do not "fix" anything -
they simply fool the system into thinking everything is OK -
ans prevents the SERVICE SUSPENSION message -
and removes the SPEED LIMITED TO 90 problem -

-------------------

now lets address your sagging rear end - so to speak -

the rear shocks incorporate air bladders -
that are inflated - to lift the rear of the car -
to maintain proper ride height -
with extra weight in the back seat or trunk -

along with the special shocks -
there is a compressor assembly -
that inflates the bladders -
it also has the exhaust solenoid
that deflated the bladders -

there are airlines between the compressor assembly and the shocks -

there is a ride height sensor
that controls the compressor assembly -

--------------

either the compressor is defective -
the ride height sensor is defective -
or a leak in the system -

-------------

if everything is messed up -
the cheapest way to solve the problem would be -
replace the shocks with
Monroe 40046 - $98.29 each - with free shipping -
and the Monroe AK29 manual fill kit - $12 -
http://www.amazon.com/gp/product/B0047D9TS0/?ie=UTF8&me=ATVPDKIKX0DER
 

·
Registered
1986 cimarron 1995 Eldorado ETC, 1997 Eldorado base
Joined
·
180 Posts
The leveling system consists of a compressor, 2 plastic air lines that run from the compressor to each rear shock bladder, and 4 height sensors (1 on each control arm - front and rear). In 1994 it is called RSS (road sensing suspension).
For the most part (simplistic), the system works as follows - at start up the rear sensors adjust the air pressure in the rear shock bladders, via the compressor and/or compressor exhaust valve (which is a part of the compressor), to the proper height. They do this by sensing how far the rear control arms have 'squatted' with relation to the weight in the car. Light weight = less air pressure and more weight = more pressure.
The "service ride control" accompanied with sagging rear shocks is most likely a failed compressor and/or compressor exhaust valve...When the bladders fail, the compressor runs too long and overheats-thus burns out.
Now, more complexly, the leveling system also adjusts as you drive. This is where the front leveling sensors apply to the leveling system. When you drive at high speeds, the sensors adjust the ride height (in the rear ONLY) for more aerodynamics. High speeds = lower rear stance.
It is NOT air ride - It IS air leveling..
Issues with the leveling system will most certainly trigger a "service ride control" message if the problem is related to a leveling sensor or compressor/compressor exhaust valve issue, AS WELL as a failed strut/shock solenoid - OR any wiring associated with the system. That's why getting the appropriate "service ride control" code is important.
You also have what is called RSS (road sensing suspension) - not to be confused with the leveling system. This senses sudden road changes, turn angles, speed changes etc. etc. - with the use of the same "leveling sensors" used with the "leveling system". The RSS system 'firms up' (off) or 'softens' (on) the appropriate shock/strut with regards to varying driving situations via a 12 volt solenoid located in the valve body of each shock/strut (total of 4). The RSS in your year is NOT variable - CVRSS (constant variable road sensing suspension) came at a later time.
Then you may have what is called SSS (speed sensitive steering) which makes your steering 'tighter' at high speeds.
ANY of these systems can cause a "service ride control" message..
The original shocks ARE available, I searched hard and got very lucky with 2 for my 95 Eldorado for $30 bucks each. Ac-delco 580-103 (or equal) http://www.ebay.com/itm/AC-DELCO-22064579-STRUT-ASMRR-SUSP-/261791003804?hash=item3cf3f5b49c&vxp=mtr.

The front struts ac delco 580-101 and 580-102 are also available.
On Amazon, the 580-101 is pictured wrong, but it is an OEM replacement active strut for $135! http://www.amazon.com/ACDelco-580-101-Assembly-select-Cadillac/dp/B000C9RMBO/ref=sr_1_1?ie=UTF8&qid=1428573890&sr=8-1&keywords=ac+delco+580-101

However the 580-102 strut is priced at $800. http://www.amazon.com/ACDelco-580-102-Assembly-select-Cadillac/dp/B000C9MDC2/ref=sr_1_1?ie=UTF8&qid=1428574129&sr=8-1&keywords=ac+delco+580-102

I have no doubt that the people selling the 580-101 strut don't know what they have, cus the picture is a mistake!
 

·
Registered
1995 Seville SLS
Joined
·
7 Posts
1 - 6 of 6 Posts
Top